Baffle assembly for a seed metering mechanism

ABSTRACT

A baffle assembly for a seed metering mechanism that is mounted in combination with a seed hopper holding a supply of seeds that are to be dispensed into a furrow with regularity by the seed metering mechanism. The seed metering mechanism includes a two-piece housing divided into a seed chamber and a vacuum chamber by a rotatable disc having a series of throughopenings or holes arranged circumferentially adjacent the perimeter of the disc. The disc picks up seeds from the seed chamber and carries them around to a discharge area of the seed metering mechanism whereat they are released for gravitational deposit into the furrow in the ground below. A seed delivery chute gravitationally directs the seeds from the seed hopper to an opening defined by the housing from which the seeds are deposited into the seed chamber. The present invention relates to the provision of a baffle assembly operable from outside of the housing to control the amount of seeds passing through the opening and passing into the seed chamber while maintaining the housing in assembled relation.

FIELD OF THE INVENTION

The present invention generally relates to seed metering mechanisms fordispensing individual seeds at a controlled rate into a seed furrow asthe seed metering mechanism advances above and across a field and, moreparticularly, to a seed baffle assembly for controlling from outside theseed metering mechanism the volume of seeds flowing from a supply seedhopper to the seed metering mechanism while maintaining the seedmetering mechanism in assembled relation.

BACKGROUND OF THE INVENTION

Seed meters of various designs have been used for sometime to dispenseseeds at a controlled rate into a seed furrow as the seed meter isadvanced above and along the seed furrow. In a typical arrangement, atractor is coupled to tow a tool bar to which are attached in agenerally parallel, spaced apart relation a plurality of planting unitswith seed meter arrangement attached thereto. Each planting unittypically includes a seed hopper for containing and carrying a largequantity of seeds to be planted or a smaller container fed from acentralized bin or large hopper, a device for opening a furrow in theground as the tractor drawn tool bar is advanced across the field overthe ground, a seed meter is coupled to the seed hopper for dispensingindividual seeds into the furrow at a controlled rate, and a furtherdevice for moving soil at the sides of the furrow to close the furrowover the seeds.

During a planting operation, the tractor typically moves across thefield at speeds of about 4 to about 8 miles per hour. The spacingbetween adjacent individual seeds in each furrow can be as little as 0.5inches or less or as much as 10 inches or more depending upon theparticular seed being planted. The seed metering mechanism therefor mustbe capable of dispensing seeds at various rates in the order of 15 to130 seeds per second or greater as well as at rates which areconsiderably less.

The many different types of seeds to be planted using a seed meteringmechanism include corn, cotton, sorghum, sugar beets, soybeans andsunflowers to name a few. As will be appreciated, such seeds varyconsiderably in size, weight and shape. For example, peanut and ediblebean seeds are among the largest seeds for planting and have elongatedirregular shapes and outer surfaces. Soybean, and pelletized seeds aresmaller and tend to be rounder and vary in shape and size. Sorghum andraw sugar beet seeds have a rounder almost spherical appearance. Sorghumseeds have a relatively smooth outer surface. On the other hand, rawsugar beet seeds have a very rough and irregular outer surfaceconfiguration. Cotton seed is small and shaped like some corn seed. Onthe other hand, corn seeds have a somewhat triangular shape withgenerally flat sides.

Despite these numerous differences in the size, shape and surfaces ofsuch seeds, seed meters are expected and are required to handle alldifferent types of seeds described above plus many more while requiringminimum effort regarding part changes and adjustments. At the same time,required spacing and depth standards of planting accuracy typicallymandate a low error rate. A missed seed or doubling of seeds isundesirable and may be tolerated only very infrequently. Suchrequirements place considerable demands upon the accuracy of the seedmetering mechanisms.

Some seed metering mechanisms used in planting operations of the typediscussed above are of the mechanical type and include a vertical orhorizontal seed plate or disc with mechanically actuated fingers orsimilarly operated mechanical devices for separating individual seedsfrom the seed disc and then dispense them into the furrow. While somemechanical seed meters are satisfactory for certain applications, theytypically suffer from a number of limitations including the limitedspeed at which they can accurately dispense seeds, and inability tohandle different type seeds without making cumbersome and extensive partchanges, and an inherent design complexity which may typically add tothe cost, wear and maintenance problems of the mechanically operatedseed dispensing mechanisms.

Alternatively, a seed metering mechanism which utilizes an air pressuredifferential has been developed in an effort to overcome some of theproblems of the mechanical seed meters. Air pressure differential seedmeters, which are commonly known as air seed meters, are generally oftwo types. The first type being the positive pressure type and thesecond type relying upon negative pressure or vacuum.

In the positive pressure type of air seed metering mechanism, air isblown into the seed chamber and onto the surface of a rotating orotherwise movable and apertured member or disc in order to create thehigher than atmospheric pressure in the chamber. This forces seeds froma seed mass onto the seed member or disc where they are retained forlater release. The apertures or holes in the rotating member or discopen to atmosphere where the individual seeds are held by the blowingair until the seeds are dispensed by interrupting the flow of air to theseeds.

While air seed meters of the positive pressure type offer certainadvantages over mechanical seed meters, they have certain limitations oftheir own which may prove to be a significant disadvantage for variousseeding applications. In an effort to fill each hole or opening with aseed as the seed disc rotates through the seed mass, a relatively highpressure differential is applied to the disc. Because the seeds are heldin place on the rotating disc or other movable member by differentialpressure resulting from positive pressure in the chamber, it is usuallynecessary that the air flow be directed through the seed mass to aid inthe depositing of individual seeds onto the disc. The air flow has beenfound to interfere with the orderly delivery of seeds from the disc and,ultimately, to the ground. In positive pressure seed meteringmechanisms, the seed hopper must be sealed to maintain pressure in thesystem. If for any reason the hopper lid comes off or the hopperotherwise becomes unsealed, the seed meter will not properly function.

Vacuum seed meters have been found to overcome some of the problems inthe positive pressure seed meters and offer more control over the seedbeing transported by the seed disc. In vacuum seed meters, a vacuumsource is typically coupled to a separate chamber on the opposite of theseed disc from the seed mass with the vacuum communicating through theapertures in the seed disc to the seed mass. The vacuum is of sufficientmagnitude such that it tends to draw seeds into the openings defined bythe disc and hold the seeds thereto as the seeds are moved through theseed disc under the influence of the moving seed disc toward the seeddischarge area of the seed metering mechanism. The openings between theouter surface of the seeds and the periphery of the openings in the discallows air to pass therethrough thereby maintaining the seeds inoperable association with the disc. Because the pressure differential atthe seed disc comes from a vacuum source on the opposite side thereofand not from the flow of air at the same side thereof as with positivepressure type seed metering mechanisms, the problem of having to directan air flow through the seed mass and on to the seed disc areeliminated.

Regardless of which type of seed metering mechanism is used, whether itbe a positive pressure seed metering mechanism or a vacuum seed meteringmechanism, there are occasions when the operator desires to gain accessto the interior of the seed metering mechanism. That is, there may be aproblem regarding blockage of one or more of the seed openings in theseed disc and the operator desires access to the interior of the housingto observe more clearly the nature of the problem. Alternatively, theoperator may desire to change the seed disc with another havingdifferent size holes or openings therein.

To effect either of these ends with seed metering mechanisms ofheretofore known designs, the cover is necessarily released from itsoperable engagement of the stationary housing secured to the seed hopperto gain access to the interior of the seed metering mechanism.Accordingly, and when the cover is released from its operableassociation with the housing, the seeds in the seed chamber of the seedmetering mechanism gravitationally fall to the ground and are lost. Thelost seed adds to the cost of the planting operation. With up to 24planting units attached to the tool bar, the loss of seed from openingeach seed metering mechanism can be significant. Alternatively, theoperator needs to position a bag or other suitable container forreceiving the seeds pouring from the seed metering mechanism after thecover is removed therefrom. As will be appreciated, holding orpositioning a bag or other suitable container to receive seeds fallingfrom the seed metering mechanism is a laborious and time consuming task.Often during a planting operation, time is at a premium and the operatordoes not have the luxury of positioning a bag to receive seeds fallingor otherwise pouring from the seed metering mechanism after the cover isremoved therefrom.

To reduce the lost of seed from the seed hopper, most seed meteringmechanisms include a seed baffle that fits across an opening throughwhich seeds are introduced from the seed hopper into the seed meteringmechanism. Another advantage involving seed baffles relates to theirability to control the amount of seed passing through the opening andfrom the hopper into the seed chamber of the seed metering mechanism. Togain access to the seed baffle, however, requires the cover of the seedmetering mechanism to be released from its operable engagement with thehousing. Thus, even with those seed metering mechanism having a seedbaffle that fits across the opening leading from the seed hopper, asignificant grain loss remains when the cover is removed and until thebaffle is closed across the opening.

Thus, there is a need and a desire for a seed baffle for a seed meteringmechanism wherein after the cover of the seed metering mechanism isremoved, or in instances where the position of the seed baffle assemblyis to be adjusted, there is minimum loss of seed and the adjustment canbe effected in the shortest time possible thus reducing downtime for theseed planting operation.

SUMMARY OF THE INVENTION

In view of the above, and in accordance with the present invention thereis provided a baffle assembly for a seed metering mechanism that ismounted in combination with a seed hopper holding a supply of seeds thatare to be dispensed into a furrow with regularity by the seed meteringmechanism. The seed metering mechanism includes a two-piece housing thatis divided into a seed chamber and a vacuum chamber by a rotatable dischaving a series of throughopenings or holes arranged circumferentiallyadjacent the perimeter of the disc. As is conventional, the disc picksup seeds from the seed chamber and carries them around to a dischargearea of the seed metering mechanism whereat they are released forgravitational deposit into the furrow in the ground below. A seeddelivery chute gravitationally directs the seeds from the seed hopper toan opening defined by the housing from which the seeds are depositedinto the seed chamber. A salient feature of the present inventionrelates to the provision of a baffle assembly for controlling fromoutside of the housing the amount of seeds passing through said openingand passing into the seed chamber while maintaining the housing inassembled relation.

In a preferred form of the invention, the housing comprises a splitassembly including a stationary housing that attaches to the seed hopperand a cover. In a most preferred form of the invention, the splithousing assembly has a generally circular configuration. The stationaryhousing has a back or rear wall with a side wall extending axiallytherefrom in a generally cylindrical-like configuration. The innersurface of the back or rear wall of the housing has a planar-likeconfiguration with a throughopening that opens to the seed chamber. Acentral hub axially extends from the inner surface of the back walltoward the cover of the seed metering mechanism. The cover of thehousing releasably attaches to the housing by a series of releasablefasteners. In a most preferred form of the invention, the cover isremovably attached to housing such that the cover is completelyremovable from the housing to enhance access to the interior of the seedmetering mechanism when required or desired.

The seed metering mechanism preferably includes a seed chute on theexterior of the back wall of the housing. In a most preferred from ofthe invention, the seed chute is integrally formed with the back walland defines a closed path extending between the seed hopper and thethroughopening leading to the seed chamber of the seed meteringmechanism. Moreover, in a preferred form of the invention, the cover ofthe split housing preferably defines a vacuum port to which a vacuumsource is connected to cause reduced pressure to be established orcreated in the vacuum chamber of the seed metering mechanism.

The seed baffle assembly of the present invention comprises a seedbaffle that is configured to fit across and over the throughopeningthrough which seeds are directed into the seed chamber. The seed bafflepreferably has a planar configuration that abuts against the innersurface of the back wall of the seed metering housing. In a mostpreferred form of the invention, the seed baffle defines an aperturethat fits over and operatively journals the central hub such that theseed baffle is arranged for arcuate movement about the central hub ofthe housing. As such, a first portion of the seed baffle is radiallydisposed on one side of the central hub while a second portion of theseed baffle is radially disposed on an opposite side of the central hub.The first portion of the seed baffle is configured to extend across theentirety of the opening in the back wall of the housing leading to theseed chamber. In a most preferred form of the invention, the housing isprovided with suitably shaped lugs for guiding the first portion of theseed baffle as it arcuately moves relative to the opening in saidhousing.

The seed baffle assembly of the present invention further includes alinkage assembly arranged on the exterior of the back wall of the seedmetering housing for permitting the seed baffle to be adjusted whilemaintaining components of the seed metering mechanism in assembledrelation. The linkage assembly has a plurality of set positions relativeto the housing. The set positions of the linkage assembly correspond todifferent positions of the seed baffle relative to the opening in thehousing thereby establishing different seed flow rates for the seedsgravitationally passing between the seed hopper and the seed chamber ofthe seed metering mechanism. In a most preferred form of the invention,a portion of the linkage assembly for controlling the seed baffle isreleasably securable to the housing of the seed metering mechanism inseveral different predetermined positions. In a most preferred form ofthe invention, the housing is provided with a series of detents thatallow the linkage assembly for controlling the seed baffle to be securedin several different predetermined positions thereby establishing thegravitational flow rate of the seeds between the seed hopper and theseed chamber of the seed metering mechanism.

The linkage assembly of the seed baffle assembly is arranged on anexterior of the seed metering mechanism. In a preferred from of theinvention, the linkage assembly is operably connected to the secondportion of the seed baffle. Thus, adjustment of the linkage assemblyresults in movement of the first portion of the seed baffle.Advantageously, the linkage assembly and thereby the seed baffle can beadjusted from outside of the housing. The adjustment of the seed bafflecan extend between a fully open position wherein the seed baffleuncovers the entirety of the opening leading to the seed chamber or afully closed position wherein the seed baffle extends across theentirety of the opening thereby effectively and operatively preventingseeds from being delivered to the seed chamber from the seed hopper.Advantageously, the seed baffle can be adjusted through any of severalintermediary positions between fully opened and fully closed.

A salient feature and object of this invention relates to the ability toadjust the seed baffle as desired without requiring removal of the coverfrom the seed housing assembly each time adjustment is desired orrequired. That is, arranging the linkage assembly in operableassociation with the seed baffle while remaining outside of the seedhousing allows the operator to adjust the seed baffle without having toopen or remove the cover from the housing. Accordingly, there are nolost seeds during the adjusting process. Accordingly, seed plantingcosts can be minimized thus leading to more cost effective plantingoperations.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic right side elevational view of a planting unitwith a seed metering mechanism in accordance with the present inventionmounted thereon;

FIG. 2 is a rear perspective view looking forwardly of a seed hopperwith a seed metering mechanism according to the present inventionmounted thereon;

FIG. 3 is an enlarged right side elevational view of the seed meteringmechanism with a fragmentary portion of a seed tube shown connectedthereto;

FIG. 4 is a front elevational view of the seed metering mechanism of thepresent invention disassembled from the seed hopper;

FIG. 5 is a left side perspective view of the seed metering mechanismaccording to the present invention;

FIG. 6 is a sectional view taken along line 6--6 of FIG. 4;

FIG. 7 is an enlarged fragmentary view of the portion encircled by line7--7 in FIG. 6;

FIG. 8 is an enlarged fragmentary view of the portion encircled by line8--8 in FIG. 6;

FIG. 9 is an exploded perspective view of the seed metering mechanism ofthe present invention;

FIG. 10 is a right perspective view of a housing component forming partof the seed metering mechanism of the present invention;

FIG. 11 is an enlarged right side view of the housing componentillustrated in FIG. 10;

FIG. 12 is a sectional view taken along line 12--12 of FIG. 3;

FIG. 13 is a sectional view taken along line 13--13 of FIG. 3;

FIG. 14 is a left side view of the housing component illustrated in FIG.10;

FIG. 15 is an enlarged left side view of a portion of the housingillustrated in FIG. 14;

FIG. 16 is an enlarged left side view of the portion of the housingencircled in FIG. 15;

FIG. 17 is a right side view of a baffle used in combination with thehousing of the present invention;

FIG. 18 is an end view of the baffle illustrated in FIG. 17;

FIG. 19 is a perspective view of a driven hub forming part of the seedmetering mechanism of the present invention;

FIG. 20 is a perspective view of a drive hub forming part of a driveassembly of the seed metering mechanism of the present invention;

FIG. 21 is a right side view of the drive hub illustrated in FIG. 20;

FIG. 22 is a rear elevational view of the drive hub illustrated in FIGS.20 and 21;

FIG. 23 is a perspective view of an agitator assembly used incombination with the seed metering mechanism of the present invention;

FIG. 24 is a right side view of the agitator assembly shown in FIG. 22;

FIG. 24A is a sectional view talken along line 24A--24A of FIG. 24;

FIG. 25 is an enlarged elevational view of a central portion of theagitator assembly showing a series of springs forming an integral partof the agitator assembly;

FIG. 26 is a sectional view taken along line 26--26 of FIG. 24;

FIG. 27 is a right side view of one form of seed metering plate to beused in combination with the seed-metering mechanism of the presentinvention;

FIG. 28 is an end view of the seed-metering plate shown in FIG. 26;

FIG. 29 is a right side view of a singulator apparatus arranged incombination with the seed-metering mechanism of the present invention;

FIG. 30 is an exploded perspective view of the singulator apparatusshown in FIG. 29;

FIG. 31 is a right side view of a base forming part of the seedsingulator;

FIG. 32 is a sectional view taken along line 32--32 of FIG. 31;

FIG. 33 is a sectional view taken along line 33--33 of FIG. 31;

FIG. 34 is a perspective view of one form of singulator mount formingpart of the singulator assembly;

FIG. 35 is a right side view of the singulator mount shown in FIG. 33;

FIG. 36 is a top elevational view, partly in section, of the singulatormount illustrated in FIG. 35;

FIG. 37 is a perspective view of another singulator mount forming partof the singulator apparatus shown in FIGS. 29 and 30;

FIG. 38 is a right side view of the singulator mount shown in FIG. 37;

FIG. 39 is a top plan view of the singulator mount shown in FIG. 38;

FIG. 40 is a perspective view of an actuator for the singulatorapparatus;

FIG. 41 is a right side view of the actuator shown in FIG. 40;

FIG. 42 is an end view of the actuator shown in FIG. 40;

FIG. 43 is a side view of a cover forming part of the singulatorapparatus of the present invention;

FIG. 44 is a sectional view taken along line 44--44 of the coverillustrated in FIG. 43;

FIG. 45 is a elevational view of a spool stud forming part of thesingulator apparatus shown in FIGS. 29 and 30;

FIG. 46 is an end view of the spool stud shown in FIG. 45;

FIG. 47 is an elevational view of one form of singulator spool that canbe used in combination with the singulator apparatus of the presentinvention;

FIG. 48 is a side view of the singulator spool illustrated in FIG. 47;

FIG. 49 is a partial sectional view taken along line 49--49 of FIG. 48;and

FIG. 50 is a partial sectional view taken along line 50--50 of FIG. 48.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in differentforms, there is shown in the drawings and will hereinafter be describeda preferred embodiment of the invention with the understanding that thepresent disclosure is to be considered as setting forth anexemplification of the present invention which is not intended to limitthe invention to the specific embodiment illustrated.

Referring now to the drawings, wherein like reference numerals indicatelike parts throughout the several views, an agricultural implement isschematically illustrated in FIG. 1 and is represented in its entiretyby reference numeral 10. Implement 10 includes an elongated tool bar 12which is supported for movement across and over fields by a plurality ofwheels (not shown) and which is adapted to be towed in a given forwarddirection by a power source such as an off-highway tractor or the like.Attached to the tool bar 12 are a plurality of planting units 14; withonly one being illustrated and described in detail and from which acomplete understanding of the present invention may be readilydetermined. As is well known in the art, the planting units 14 aremounted in side-by-side relation relative to each other along the lengthof the tool bar 12.

In the illustrated embodiment, each planting unit 14 preferably includesa conventional furrow opening apparatus generally indicated in FIG. 1 byreference numeral 18. As is known in the art, the furrow opening unit 18preferably includes a pair of lateral spaced furrow opener discs 21, afurrow forming point, and an opener shoe 24. Alternatively, and withoutdetracting or departing from the spirit and scope of the presentinvention, the planting unit 14 can be provided with a runner openertype for providing a furrow in the ground. The planting unit 14 furtherincludes a pair of furrow closer discs 26 and a press wheel 28 arrangedin fore-and-at relationship relative to each other.

A seed hopper 30 is likewise carried on each planting unit 14. Thepurpose of the seed hopper 30 is to provide storage for seed materialthat is to be gravitationally deposited to the ground as the plantingunit moves over and across the field. It will be appreciated that ahopper container, smaller than that exemplified in the drawings, andconnected to a centralized bin or large hopper would equally sufficewithout detracting or departing from the spirit and scope of the presentinvention. In the illustrated embodiment, a seed metering mechanism orapparatus 32 is arranged in seed receiving relation relative to thehopper 30 and, in the illustrated embodiment, forms part of the plantingunit 14. The purpose of the seed metering apparatus or mechanism 32 isto uniformly release seeds received from the seed hopper 30 for depositonto the ground. To facilitate delivery of seeds from the seed meteringmechanism 32 to the ground, a vertically disposed seed tube 34 ismounted on the planting unit 14. The seed tube 34 is preferably of thetype disclosed in co-pending and co-assigned patent application Ser. No.08/581,444, filed Dec. 29, 1995, in the illustrated embodiment, a thefull disclosure of which is incorporated herein by reference. Suffice itto say, the seed tube 34 defines a vertical passage 36 through whichseeds are delivered to the ground.

As the power source or tractor pulls the tool bar 12 across and over theground, the furrow opening apparatus 18 operates to open a furrow in theground. Seeds from the hopper 30 flow into the seed metering mechanism32 from whence seeds are introduced at a controlled rate into the seedtube 34 to uniformly move through the vertical passage 36 defined bytube 34 and are, ultimately, deposited onto the ground. The furrowcloser 26 trails the furrow opening apparatus 18 and, as the implement10 is drawn across the field, serves to close the furrow together andover the seed dispensed by the seed metering mechanism 32 into thefurrow. The trailing press wheel 28 serves to compact the soil closedover the seeds.

In the illustrated embodiment, a pesticide hopper 38 is mounted toward arear end of each planting unit 14. Hopper 38 preferably includes aninsecticide and is provided with conventional dispensing means forapplying controlled amounts of insecticide where desired in connectionwith the planting of seeds by each planting unit 14.

According to the present invention, the vacuum seed metering mechanismor apparatus 32 is mounted to and movable with the hopper 30 relative toframe structure 33 (FIG. 1) of the seed planting unit 14 and relative tothe seed tube 34. Moreover, the hopper 30 is mounted on and removablefrom the planting unit 14 in a conventional manner. As shown in FIG. 2,the seed metering mechanism 32 includes a split housing assembly 40arranged toward the bottom of and in seed receiving relation relative tothe seed hopper 30. The seed metering apparatus 32 mounted to eachplanting unit 14 (FIG. 1) is individually connected via a suitableflexible conduit 42 to a common vacuum source (not shown) suitablymounted for movement over and across the field.

As shown in FIGS. 2 through 5, the housing assembly 40 of the seedmetering mechanism 32 has a generally cylindrical-like configurationmeasuring about 300 mm. in diameter. The housing assembly 40 iscomprised of a housing or shell 44 that is rigidly secured to the seedhopper 30 and a cover or shell 46 releasably connected to shell 44. Inthe preferred form of the invention, the cover 46 is completelyremovable from the housing 44 when access to the interior of the seedmetering mechanism 32 is desired or required. Preferably, a series ofmanually releasable fasteners 48 are equidistantly arranged about theperiphery of the housing assembly 40 for releasably fastening thehousing 44 and cover 46 in operable and substantially air tight relationrelative to each other. In the illustrated embodiment, three fasteners48 are provided for releasably securing the cover 46 to the housing 44.

The cover 46 of the split housing assembly 40 is preferably formed as aunitary or one-piece member that is formed with sealing surfaces andsuitable cutoffs as an integral part thereof. As such, the seed meteringmechanism of the present invention does not require additional parts tobe added thereto to effect sealing such as rubber seals and the like. Inthe illustrated embodiment, the cover 46 is formed of a rigid nylon orthermoplastic material containing conventional antistat and/or other lowfriction agents such that no graphite, talc, or slick additives need tobe used in combination with the seed metering mechanism of the presentinvention during operation thereof. Moreover, and as shown in FIG. 6,cover 46 of the split housing assembly 40 has an arcuate shaped chamber50 extending about 270° and adjacent the periphery of the cover 46. Aswill be described in detail hereinafter, an exhaust or suction port 52opens to the chamber 50 intermediate opposite ends thereof. As isconventional, the flexible conduit 42 is exteriorly connected to theexhaust port 52 such that a vacuum or negative pressure may be createdin the chamber 50 when the cover 46 is fastened to the housing 44.

Chamber 50 in housing 46 is partially defined by a first annular orcircular flat sealing face 54 formed integral with an inner surface 56of the cover 46. Also arranged on the inner surface 56 of cover 46, inradially spaced congruent relation from the sealing face 54, is a secondsealing face 58 that is likewise formed integral with the inner surface56 of cover 46. Notably, the sealing faces 54 and 58 are arranged ingenerally planar relation relative to each other are formed integralwith the cover 46 thus eliminating the need or requirement foradditional separate rubber seals. Moreover, and as shown in FIG. 6,outwardly spaced from the sealing face 58, cover 46 defines a flatcircular lip area 60 extending radially outwardly to the periphery ofthe cover 46. Notably, both the first and second seating faces 54 and 58axially project from the inner surface 56 of the cover 44 beyond thecircular lip area 60. Cover 46 furthermore defines a leg portion 62 thatis generally coplanar with the flat lip area 60 and which extendstangentially away from one end of chamber 50.

As shown in FIG. 7, the inner and outer radially spaced sealing faces 54and 58, respectively, are joined, at one end, by a first radial web 64that separates a leading end of vacuum chamber 50 from a seed dischargearea of the seed metering mechanism 32 as will be discussed in detailbelow. In the illustrated form of the invention, the radial web 64 ispreferably formed integrally with the cover 46 and has a flat sealingface 66 that is generally coplanar with the sealing faces 54 and 58 ofcover 46.

As shown in FIG. 8, the opposite or trailing end of chamber 50 isdefined by a second radial web 68 defining a vacuum cutoff for thechamber 50. As shown, the radial web 68 is preferably formed integralwith the cover 46 and likewise has a flat sealing face 70 formed planarwith the sealing faces 54 and 58 of cover 46. Notably, cover 46 furtherdefines an inclined ramp 72 radially extending through the chamber 50and toward the vacuum cutoff 58.

Turning now to FIG. 9, component assemblies of a preferred form of theseed metering mechanism 32 of the present invention are schematicallyillustrated in exploded perspective relative to each other. As shown,the seed metering mechanism 32 of the present invention preferablycomprises the housing 44, a manually operated baffle assembly 100 thatis operably adjusted from outside the housing assembly 40 of the seedmetering mechanism 32, a drive assembly 200, an agitator assembly 300for inhibiting seeds from compacting within the housing assembly 32, aseed disc or plate 400 that operably divides the interior of the housingassembly 32 into a seed chamber 74 (FIG. 4) between one side of the seedplate 400 and the interior of housing 44 and the vacuum chamber 50between the opposite side of the seed plate or disc 400 and the cover46, a singulator assembly 500 for inhibiting more than one seed frombeing advanced by the seed plate or disc 400 to the discharge area ofthe seed metering mechanism 32, a vibration mechanism 800 forfacilitating the release of seeds from the disc 400 in the dischargearea of the seed metering mechanism 32, and the cover 46 for closing theseed metering mechanism 32.

As shown in FIGS. 10 and 11, housing 44 of the seed metering mechanism32 is preferably formed from a metal material and includes a generallyplanar back wall 76 having inner and outer surfaces 78 and 80,respectively. An annular hub 82 is formed at the center of the housing44 and axially projects inwardly from the inner surface 78. The annularhub 82 defines a central bore 83 defining a longitudinal axis 84 for theseed metering mechanism 32. As shown in FIGS. 12 and 13, the driveassembly 200 axially extends through and is rotatably mounted within thehub 82 of housing 44. As shown in FIGS. 9 through 11, housing 44 definesa circumferential skirt or rim 85 that axially projects forwardly fromthe inner surface 78 in surrounding relation to a substantial portion ofouter periphery of housing 44.

As shown in FIGS. 12 and 13, an annular portion of the edge of rim 85cooperates and combines with the flat lip area 60 on the inner surface56 of cover 46 to close the housing assembly 32. Notably, the areasurrounded by rim 85 and between the seed plate or disc 400 and theinner surface 78 of the housing 44 defines a seed reservoir or chamber86 wherein seeds are stored.

As shown in FIGS. 10 and 11, the annular rim or skirt 85 has arcuateareas 88 and 90 that are recessed from the reminder of edge. When thecover 46 is fastened to the housing 44, these recessed areas 88, 90define circumferentially extending openings 89 (FIG. 4) and 91 (FIG. 13)allowing atmospheric air to enter the housing assembly 32 and maintainthe seeds releasably attached to the disc 400 as a function of thedifferential air pressures between the suction chamber 50 and theopposite side of the housing 32.

As shown in FIGS. 5, 10 and 14, the outer surface 80 of housing 44defines a lug 92 which facilitates connection of the housing assembly 32to the hopper 30. As shown, housing 44 further defines a chute 94 thatallows and directs the gravitational flow of seed between the hopper 30(FIG. 5) and the seed reservoir or chamber 86 (FIG. 12). In this regard,the back wall 76 of housing 44 defines an opening 96 (FIGS. 10 and 11)that allows seeds to pass from the chute 94 into the seed reservoir areaor chamber 86 of the seed housing assembly 32.

Referring to FIGS. 10 and 11, housing 44 further defines a wall 97spaced radially inwardly from rim 85 and axially projecting from theinner surface 76 of housing 44. The space or open area 95 between therim 85 and wall 97 defines a seed exhaust area 98 for the seed meteringmechanism 32. As shown, the exhaust area 98 opens at its lower end tothe seed tube 34 (FIG. 1) and through which the seeds released from theseed plate 400 gravitationally move, ultimately, for deposit onto theground. In this regard, the back wall 76 of housing 44 defines a seriesof vertically spaced openings 99 that allow atmospheric air to pass intothe exhaust area 98 and facilitate the flow of seeds toward the seedtube 34 by eliminating or significantly reducing the air drawn upwardlyinto the seed discharge area 98 of the seed metering mechanism. In thepreferred embodiment of the invention, and as shown in FIGS. 15 and 16,the openings 99 preferably have slotted or elongated configurations.

Returning to FIG. 3, when the cover 46 is releasably attached to thehousing 44, a substantial portion of chamber 50 extends through the seedreservoir area 86 of housing 44. Moreover, the leading end of the vacuumchamber 50 is disposed proximate to but remains outside of the dischargechute 98 of the housing 44. At its other end, suction chamber 50terminates toward the upper end of the discharge area or chute 98 suchthat seeds released from the seed plate 400 pass downwardly into thedischarge chute 98 and pass gravitationally toward the seed tube 34.Moreover, with the cover 46 so arranged on the housing 44, leg portion62 of the housing overlies and closes the open side of the dischargechute 98 defined by housing 44 to prevent seeds released from the seedplate from inadvertently escaping from the housing assembly 32.

The purpose of the seed baffle assembly 100 is to control the seed levelin the seed reservoir 86 from outside of the housing assembly 40. Withthe present invention, and as mentioned above, the cover 46 ispreferably removable from the housing 44. After the cover 46 is removedand the seed plate 400 is removed, the seeds in the reservoir 86 willtend to pour out to the ground. Moreover, if there is nothing to closethe opening 96 at the bottom of the chute 94, the seeds in the supplyhopper 30 will likewise tend to pour onto the ground. Accordingly, thepresent invention provides the seed baffle assembly 100 for selectivelyallowing the operator to choose the level of seed mass in the reservoir86 from outside of the housing 44. That is, and unlike other seedmetering mechanisms, the seed baffle assembly 100 is adjustable from theoutside and does not require the operator to gain access to the interiorof the seed metering mechanism 32 in order to close off the opening 96leading from the hopper 30.

As shown in FIGS. 9, 17 and 18, the seed baffle assembly 100 comprises aseed baffle 102 having a general planar configuration. The seed baffle102 defines a generally central throughbore 103 that allows the seedbaffle 102 to be mounted for rotation about the hub 82 of the housing 44of housing assembly 40. As shown in FIG. 12, the seed baffle 102 isconfigured to mount in abutting and generally sealing relationship withthe inner surface 78 of the housing 44. Notably, the profile of the seedbaffle 102 is such that the baffle 102, when properly positionedrelative to housing 44 of the housing assembly 40, can completely closethe opening 96 (FIG. 11) at the bottom of the chute 94 through whichseed is directed into the seed reservoir of housing 44.

As shown in FIGS. 14 and 15, the seed baffle assembly 100 furtherincludes a linkage assembly 106 that is exteriorly manipulated fromoutside of housing 44 to effect the disposition of the seed baffle 102and thereby control the operable size of the opening 96 in the housing44. Returning to FIG. 11, the rear wall 76 of the housing 44 defines anarcuate slot 108 that extends through the wall 76 and has a radiusconcentric with the longitudinal axis 84 of the hub 82. The exteriorsurface 80 of the rear wall 76 of housing 44 furthermore defines a pivot110 (FIG. 15).

In the illustrated embodiment of the invention, and as shown in FIGS. 14and 15, the linkage assembly 106 of the seed baffle assembly 100preferably comprises a manually operated elongated lever 112 thatextends parallel to the rear wall 76 of housing 44 and is pivotallyconnected intermediate its ends to a pivot 110 defined on the exterior80 of housing wall 76. A free end 113 of lever 112 extends beyond theperiphery of the housing 44. An elongated link section 114 of lever 112extends parallel to an exterior side 80 of wall 76 and away from thepivot 110 of lever 112. As will be appreciated, movement of lever 112will result in pivotal movement of the link section 114. A secondelongated link 116, arranged parallel to and extending adjacent theouter surface 80 of wall 76, is articulately joined, at one end, to thefree end of link section 114 of lever 112. At its opposite end, link 116is connected through the slot 108 to the seed baffle 102 (FIG. 17). Theconnection between and the travel of link 116 of linkage assembly 106 isguided by the arcuate shape of the slot 108. As will be appreciated,opposite ends of the slot 108 limit the travel of the linkage 106 andthereby the travel of the seed baffle 102 relative to the opening 96 inthe rear wall 76 of the housing 44.

As shown in FIGS. 10, 14 and 15, the exterior surface 80 of wall 76 onhousing 44 defines a flange 118 preferably formed integral with thehousing 44 and extending generally normal to the major exterior surface80 of the housing 44. The flange 118 defines a series of verticallyspaced detents or notches 120, 122, 124 and 126. Each notch or detent120, 122, 124 and 126 opens to a common side of flange 118 to releasablyaccommodate the lever 112 therewithin.

In a preferred form of the invention, the lever 112 is sized such thatthe free end thereof extends radially past the flange 118 for easy andready manual engagement. In a most preferred form of the invention, andto facilitate insertion of the lever 112 into the respective notch 120,122, 124 or 126, in the area where the lever 112 passes in proximity tothe notches 120, 122, 124 and 126, the lever 112 is configured with agenerally circular cross-sectional configuration. The thickness of eachnotch or recess 120, 122, 124 and 126 defined on flange 118 closelyproximates the diameter of the lever 112. By such construction, thelever 112 can be manually and readily shifted from one notch to theother while the respective notches furthermore serve to releasablymaintain the lever 112 in position selectively chosen by the operatorduring the functioning of the seed metering mechanism 32. As will beappreciated, movement of the lever 112 likewise effects displacement ofthe seed baffle 102 relative to the opening 96 thereby regulating theflow of seeds through the opening and into the seed reservoir 86.

In the illustrated form of the invention shown in FIG. 13, the notches120 and 126 define the extreme limits of movement of the seed baffle 102relative to the opening 96 leading to the seed reservoir 86. Moreover,it should be readily appreciated that less or more notches than thatshown can be arranged on the housing 44 without detracting or departingfrom the spirit and scope of the present invention.

A schematic illustration of the drive mechanism 200 is provided in FIGS.12 and 13. As shown, the drive mechanism 200 comprises a driven shaft202 that is rotatably mounted within the bore 83 defined in the housing44 and coaxial with the longitudinal axis 84 of the seed meter assembly32. As shown, the driven shaft 202 has a center section 204 with reduceddiameter sections 206 and 208 axially extending from opposite sides ofthe center section 204 and extending to respective free ends of theshaft 202. Notably, the differences in diameter between the centersection 204 and the reduced diameter section 208 results in theprovision of a radial shoulder 210 therebetween. In the illustratedembodiment, the radial shoulder 210 on the shaft 202 abuts with aninward projection defined by the hub 82 on the rear wall 76 of housing44 thereby limiting axial displacement of the driven shaft 202 to theleft as shown in FIG. 6.

The reduced diameter section 206 projects outwardly from the rear wall76 of the housing 44 and has a driven coupler 214 carried at the freeend thereof for releasably coupling the driven shaft 202 to aconventional drive coupler mechanism (not shown) that typically formspart of the planting unit 14. As shown in FIGS. 12, 13 and 19, thedriven coupler 214 has a mounting hub 216 that fits about and isreleasably connected to the reduced diameter section 206 of the drivenshaft 202 as with a suitable pin 218 or the like. The driven coupler 214furthermore includes a driven lug 220 that axially extends generallyparallel to but is disposed in radially spaced relation relative to thelongitudinal axis 84 of the seed metering assembly 32. As will beappreciated, movement imparted to the driven lug 220 will likewise betransferred to the mounting hub 216 and thereby to the driven shaft 202.As is well known in the art, the driven lug 220 mates with a drive lug(not shown) provided on a conventional and well known drive coupler (notshown) that is disposed on the outside of the exterior surface 80 of thehousing 44 and which conventionally forms part of the drive couplermechanism. As will be appreciated by those skilled in the art, usingonly a single or one driven lug 220 on the drive mechanism 200facilitates removal, when necessary, of the hopper 30 and the seedmetering mechanism 32 from the planting unit 14.

A drive rotor 230 is mounted at the opposite end of driven shaft 202 onthe reduced diameter section 208. As shown in FIGS. 20, 21 and 22, thedrive rotor 230 comprises a mounting hub 232 that fits about and isreleasably secured to the reduced diameter section 208 of the drivenshaft 202 as with a suitable pin 234 (FIG. 22) or the like. Notably, andas shown in FIGS. 12 and 13, the mounting hub 232 has a greater diameterthan the bore 83 defined in the hub 82 and through which the reduceddiameter portion 208 axially extends. Accordingly, when the drive rotor230 is fastened to the driven shaft 202, the driven shaft 202 isprevented from moving to the right as shown in FIGS. 12 and 13 by themounting hub 232 abutting with the hub 82 in the housing 44 of the seedmetering housing assembly 32.

Returning to FIGS. 20 through 22, the drive rotor 230 further includesfirst and second driving sections 240 and 250, respectively, that arearranged in centered relation about the longitudinal axis 84 of the seedmetering mechanism 32. As shown, the drive rotor 230 includes anenlarged disc-like member 236 defining a central bore 237 and havinggenerally planar axially spaced and generally parallel major surfaces238 and 239, respectively, radially extending outwardly to the peripheryof the drive rotor 230. Projecting axially outwardly from the majorsurface 238 of the disc-like member 236 are the first and second drivingsections 240 and 250, respectively.

The first driving section 240 comprises a multi-sided configurationwherein each of the sides of the driving section 240 are equal to eachother but define a flat surface area 241 that is axially spaced from andis smaller than the major surface 238 of the disc-like member 236 suchthat surface 238 acts as a stop for the axial arrangement of subsequentmembers or pieces placed thereabout as will be described in detailhereinafter. In the illustrated embodiment, driving section 240 has agenerally triangular configuration including side surfaces 242, 244 and246 that axially project from the major surface 238 of the disc-likemember 236 of drive rotor 230. It will be appreciated, however, thatother configurations for the driving section 240 would equally sufficewithout detracting or departing from the spirit and scope of the presentinvention. For example, the first driving section 240 could beconfigured with four equal sides or five equal sides that axiallyproject away from the planar surface 238 of the disc-like member 236.

The second driving section 250 of the drive rotor 230 likewise comprisesa multi-sided configuration that axially extends beyond the firstdriving section 240. In the illustrated embodiment, the second drivesection 250 comprises a plurality of equally spaced and axiallyelongated pins 252. Moreover, the pins 252 are all arranged in a commonradial distance from the longitudinal axis 84 of the seed meteringmechanism 32. In the illustrated embodiment, each pin 252 has agenerally cylindrical like configuration between opposite ends thereof.It will be appreciated, however, that other pin configurations wouldequally suffice without detracting or departing from the spirit andscope of the present invention. Moreover, each pin 252 has a chamferedconfiguration 254 at the distal end thereof for promoting axialplacement of the seed metering disc 400 thereover. In the illustratedembodiment, the pins 252 are integrally formed with the disc-like member236. It will be appreciated, however, that the pins 252 could be formedseparate from and then added to the disc-like member 236.

The agitator assembly 300 is arranged in driving relation relative tothe drive rotor 230 of the drive assembly 200. As mentioned, the purposeof the agitator assembly is to inhibit seeds from compacting within theseed reservoir 86 of the housing assembly 32.

In the illustrated embodiment, and as shown in FIGS. 23 and 24, theagitator assembly 300 includes a disc shaped rotor 302 having a centralhub 304 and a plurality of flexible and readily replaceable fingers 306radially extending from the rotor 302. In the illustrated embodiment,the central hub 304 is axially displaced from the remainder of the rotor302 and has first and second generally parallel side surfaces 308 and310, respectively. Notably, the axial distance separating the first andsecond surfaces 308, 310 of the central hub 304 of rotor 302 isgenerally equal to the axial distance the side surfaces 242, 244 and 246project away from the major surface of the disc shaped member 236 ofdrive rotor 230 of the drive section 240.

The central hub 304 of agitator assembly 300 furthermore defines acentrally located through opening 312 that is configured tosubstantially correspond to the cross-sectional configuration of thefirst driving section 240 of drive assembly 200. That is, in theillustrated embodiment, the opening 312 in the rotor 302 of the agitatorassembly 300 has a generally triangular configuration that substantiallycorresponds to the triangular shape of the first driving section 240. Itwill be appreciated however, that changes in the configuration of thefirst driving section of drive assembly 200 will be equally reflected inthe shape and size of the opening 312 in the rotor 302 of the agitatorassembly 300. As such, when the rotor 302 of agitator assembly 300 ismounted on the first drive section of the drive rotor 230 of driveassembly 200, a drive connection is established between the drive rotor230 of drive assembly 200 and the rotor 302 of agitator assembly 300.

The remaining portion of the disc shaped rotor 302 radially extendingfrom the central hub 304 has generally parallel first and second sidesurfaces 318 and 320, respectively. Toward the periphery of the rotor302 there are provided a series of equally disposed receptacles 322 forreleasably accommodating one end of each finger 306. Each receptacle 322has inclined surfaces 324 and 326 projecting angularly away from theside surface 318 of the rotor 302. Such receptacles 322 act as fins orstep-like extrusions. As such, and upon rotation of the rotor 302, theseed mass in the seed reservoir 86 defined by the housing 44 of thehousing assembly 32, is agitated by the receptacles 322 in a mannerpreventing the seed mass from compacting itself during operation of theseed metering mechanism 32. Similarly, the fingers 306 projectingradially outwardly from each receptacle 322 tends to agitate the seedmass in the housing 44 upon rotation of the rotor 302.

In a preferred form of the invention, the fingers 306 projectingoutwardly from the rotor 302 range in size from about 0.080 inches toabout 0.095 inches in diameter and are preferably made from a nylon-likematerial or other suitable flexible material such as that used in grasstrimming machines. Preferably, the fingers 306 radially extend outwardlyfor a distance equal to about 150 mm. Notably, the fingers 306 aredisposed in a swept back configuration relative to the direction ofrotation of the rotor 302. As such, should the fingers 306 engage anobject along their path of travel, the fingers 306 merely tend todeflect around and out of the way of the obstruction without damagingeither the obstruction or the finger 306. In a most preferred form ofthe invention, one end of each finger 306 is releasably accommodatedwithin a hole or opening 330 defined by each receptacle 322 on the rotor302. Accordingly, repair or replacement of the fingers 306 is readilyand easily effected. It will be appreciated, however, that it islikewise within the spirit and scope of the present invention to formthe fingers 306 as permanent cast or integral part of the rotor 302.

As shown in FIGS. 12 and 13, the rotor 302 of the agitator assembly 300furthermore serves to axially urge the seed plate 400 in an axialdirection and toward the cover 46 of the housing assembly 32. In thisregard, and as shown in FIGS. 12, 13 and 26, the rotor 302 of theagitator assembly 300 includes spring structure 350 for resilientlyurging the seed plate 400 toward the cover 46 of the housing assembly 32to maintain a sealing relationship between the seed disc 400 and thecover 46 throughout operation of the seed metering mechanism 32.

In the illustrated form of the invention, the spring structure 350comprises a plurality of leaf springs 352 that are preferably formedintegrally with the rotor 302. As shown in FIGS. 25 and 26, and in thearea of the central hub 304, preferably adjacent and parallel to eachside of opening 312, the rotor 302 includes a plurality of fingers 352.In the illustrated embodiment, each finger 352 has a cantileveredconfiguration. That is, each finger 352 is joined at one end to therotor 302. The free end of each finger 352, however, axially projectsbeyond side surface 308 of the rotor 302 to resiliently engage the seedplate 400.

During a seed planting operation, the tractor typically moves over theground at a speed of about 4 to about 8 miles per hour. Seed spacingswithin the furrows can range between as little as 0.5 inches to as muchas 10 inches between adjacent seeds. Accordingly, the rate of dischargefrom the vacuum seed metering mechanism 32 of the present invention canvary greatly from a very low discharge rate on the order of twenty seedsper second or less such as when the tractor is traveling at only about 4miles per hour and up to 10 inch seed spacing is required to a very highrate on the order of about 130 seeds per second or greater where thetractor is traveling at a considerably faster speed and a seed spacingas little as 0.5 inches is required. It will be appreciated, therefore,that the seed metering mechanism 32 of the present invention must becapable of dispensing seeds at a rate which can vary considerably. Tofurther complicate matters, the seed metering mechanism 32 of thepresent invention must be capable of handling different seeds ofdifferent sizes and surface characteristics. Ultimately, the importantfactor to be mastered relates to the ability to dispense seedsaccurately.

In this regard, an advantageous feature of the present invention relatesto the ability of quickly and easily change seed discs to accommodatethe particular seed being planted. Another advantageous feature that isinherent with the design disclosed by the present invention relates tothe ability to change seed discs without requiring the use of tools orother fasteners thereby significantly reducing the downtime incurredupon replacement or changing of the seed disc. Suffice it to say, and asshown in FIGS. 27 and 28, the seed disc 400 is typically comprised of ametal material. It is also within the spirit and scope of the presentinvention to fabricate the seed disc 400 from a suitable plasticmaterial. In either embodiment, the seed disc 400 measures about 300 mm.in diameter. The 300 mm. size of seed disc 400 is significantly greaterthan any seed discs currently known in the art and allows greaterversatility in planting operations. Each seed disc 400 has a diametergreater than the diameter of the radially outermost sealing face 58 onthe cover 46 of the housing assembly 40.

The seed disc 400 has planar or flat first and second surfaces 402 and404, respectively, extending generally parallel to each other. The seeddisc 400 furthermore has a plurality of apertures 410 therein arrangedin a circumferential row adjacent but inside of a circular outer edge412. Each aperture 410 extends through the thickness of the seed disc400 between the first and second surfaces 402 and 404, respectively, ofthe disc 400. As will be readily appreciated by those skilled in theart, and without departing or detracting from the spirit and scope ofthe present invention, the seed disc 400 can include additional rows ofapertures (not shown) arranged closely adjacent and concentric to thefirst row of apertures 410. Notably, the sides or surfaces 402 and 404of the disc 400 in the area of each opening is substantially planar orflat with the remainder of the disc 400. That is, the seed disc 400 isvoid of any recesses or voids arranged in surrounding relation to theopenings 410. The flat configuration of the plate or disc 400 across theentirety thereof and especially in the area of the openings 410 reducesfrictional contact of the outer surface of the seeds when they arereleased from the disc in the discharge area 98 of the seed meteringmechanism.

As shown in FIG. 27, and toward the center thereof, each seed disc 400includes a plurality of openings or drive sockets 420 that areequidistantly arranged relative to each other about a common diameter.Notably, the spacing between the openings 420 is equal to the spacingbetween the driving pins 252 of the second driving section 250 on thedrive assembly 200. Moreover, the shape and size of the apertures 420 indiscs 400 correspond to the shape of the pins 252 of the second drivingsection 250 of drive rotor 230. An important benefit is yielded by suchconstruction. Because the disc 400 is mounted on the driving section 250of drive rotor 230, the disc 400 and the openings 410 provided thereinturn about a fixed axis 84 of rotation. Accordingly, the openings 410move along a predetermined path of travel as the disc 400 turns orrotates within the housing assembly 40. Moreover, and as will be readilyappreciated, different discs 400 are readily interchangeable within theseed metering mechanism 32 to accommodate different seed spacings and/orseeds having particular surface characteristics without the use of toolsor fasteners. Notwithstanding the size of the seed disc 400, theopenings 410 thereon travel about a predetermined path of travel betweenthe seed chamber 86 and the discharge area 98 of the seed meteringmechanism.

As stressed throughout, an important aspect of seed metering mechanism32 of the present invention relates to the ability to dispense the seedsto the ground with accuracy. This means that one seed and no more thanone seed is planted at any desired location along the length of thefurrow. As well known in the industry, dispensing or discharging morethan one seed into the furrow at any single location, sometimes referredto as "doubling", is undesirable at the very least and is unacceptablefor the majority of planting operations. The typical unavailability ofsuitable nutriments in the soil will simply not sustain or support thepresence of two seeds at any single location.

For these and other reasons, and as shown in FIG. 29, the seed meteringmechanism 32 of the present invention furthermore includes a singulatorassembly 500. During operation of the seed metering mechanism 32 of thepresent invention, a suction is created in chamber 50 of housing 46. Assuch, and as the apertures 410 on the seed disc 400 move through theseed mass in the seed reservoir 86 of housing 44, one or more seedreleasably attach themselves to the openings 410 in the seed disc underthe influence of pressure differentials. As the seed disc 400 isdrivingly rotated, the one or more seeds operably associated with eachopening or aperture 410 moves with the seed disc toward the dischargearea of the seed metering mechanism 32. Intermediate the location whereat the seeds operably attach themselves to the seed disc 400 and theseed discharge area of the seed dispensing mechanism from which theseeds gravitationally fall to the ground, the singulator assembly 500 ofthe present invention is provided to insure that one and only one seedis present in each opening or aperture 410 as the particular seed pocketor opening approaches the discharge area of the seed dispensingmechanism 32. The seed singulator mechanism is indicated generally byreference numeral 500 in FIG. 29. In the illustrated form of theinvention, the singulator assembly 500 is shown attached to the backwall78 of housing 44 of the housing assembly 40 as through a plurality ofsuitable fasteners 502 and 504 and is less sensitive to revolving speedof the seed disc 400 than are known seed singulator devices.

Turning to FIG. 30, the singulator assembly 500 is shown in explodedperspective view. As shown, the singulator assembly comprises a base510, a pair of manually movable brackets 530 and 550, a manuallyoperated adjustment mechanism 570, and a cover 590. Notably, one of theunique features of the present invention concerns the ability of thecomponent parts of the singulator assembly 500 to be assembled andadjusted relative to each other without the use of screws or otherfasteners. Accordingly, no tools are required for assembly or adjustmentof the singulator assembly of the present invention thereby reducingdowntime normally incurred during the planting operation when adjustmentof the seed singulator is required or desired. Another salient aspect ofthe singular assembly 500 relates to the provision of at least threesingulator spools 700 that are mounted in specifically spaced relationrelative to the path of travel of the apertures 410 of the seed disc400.

Turning now to FIGS. 31 through 33, the base 510 of the singulatorassembly 500 includes a generally rectangular back wall 512 having aback side 513 and a front side 514. Preferably, wall 512 of base 510further includes a closed rim 515 extending about the peripheral edge ofthe back wall 512 and axially away from the front side 514 to define anenclosure or open cavity 516. A pair of vertical disposed andhorizontally spaced rails 518 and 520, respectively, are provided withinthe enclosure 516. As shown in FIG. 31, the rails 518 and 520 arepreferably integrally formed with the base 510. It will be appreciated,however, that rails 518, 520, which are independently formed relative tothe base 510, would equally suffice. Apertured flanges 522 and 524extend outwardly from the base 510 so as to allow releasable affixationof the base 510 to the housing 44 of the housing assembly as withsuitable fasteners. Moreover, base 510 furthermore defines a centralthroughbore or opening 526 with radially elongated slots 527 and 528that pass entirely through the base 510. The slots 527 and 528 arearranged in diametrically opposed relation relative to each other and ingenerally concentric relationship relative to the bore or opening 526.

Bracket 530 is shown in FIGS. 34 through 36. As shown, bracket 530includes a slidable member 532 that is preferably formed from hardplastic or nylon and is configured to slidably fit for vertical movementwithin the recess or opening 516 of base 510. Bracket member 532includes a top surface 534 and a bottom surface 536. A pair ofvertically disposed and horizontally spaced channels 538 and 540,respectively, are provided and extend along the bottom surface 536 ofthe bracket member 532. Notably, the size and spacing of the channels538 and 540 are complementary to the size and spacing of the rails 518and 520 on the base 510. Bracket member 532 further defines a pluralityof horizontally spaced and internally threaded recesses 542, 544 and546. The threaded recesses 542, 544 and 546 defined by bracket 532 arelocated in circumferentially spaced relation relative to each other on acommon line of centers or a radius which is generally equal to theradius about which the holes or apertures 410 in the seed disc 400 aredisposed. Bracket 532 further defines an elongated generally horizontalslot or opening 548 that passes between and opens to both the top andbottom surfaces 534 and 536, respectively, of bracket member 532.

Bracket 550 is shown in FIGS. 37 through 39. As shown, bracket 550includes a slidable member 552 that is preferably formed from hardplastic or nylon and is configured to slidably fit for vertical movementwithin the recess or opening 516 of base 510 in vertically disposedrelation to bracket 530. Bracket member 552 includes a top surface 554and a bottom surface 556. A pair of vertically disposed and horizontallyspaced channels 558 and 560, respectively, are provided and extend alongthe bottom surface 556 of the bracket member 552. Notably, the size andspacing of the channels 558 and 560 are complementary to the size andspacing of the rails 518 and 520 on the base 510. Bracket member 552further defines a plurality of horizontally spaced and internallythreaded recesses 562, 564 and 566. The threaded recesses 562, 564 and566 defined by bracket 552 are likewise located on a common radius whichis generally equal to the radius about which the holes or apertures 410in the seed disc 400 are disposed. Bracket 552 further defines anelongated generally horizontal slot or opening 568 that passes betweenand opens to both the top and bottom surfaces 554 and 556, respectively,of bracket member 552.

The manually operated adjustment mechanism 570 for the singulatorassembly is shown in FIGS. 40 through 42. As shown, the adjustmentmechanism 570 comprises an elongated lever 572. The lower end of lever572 is provided with a mounting pin 574 and a pair of actuating pins 576and 578 disposed in equally spaced relation and on opposite sides of themounting pin 574. Notably, the mounting pin 574 is preferably formedintegral with the lever 572 which is formed from plastic or nylon.

With the brackets 530 and 550 arranged in the enclosure 516 defined bybase 510, the lever 572 is arranged on the backside 513 of the base 510and the mounting pin 574 is inserted endwise through the opening 526 inthe base 510. Notably, the diameter of the mounting pin 574 issubstantially equal to the diameter of the hole or opening 526 in thebase 510 such that the lever 572 is permitted to pivotally move and rockabout an axis 575 defined by the mounting pin 574. Similarly, theactuating pins 576 and 578 on the lever 572 project endwise through thearcuate slots 527 and 528, respectively, of the base 510. As such, theactuating pin 576 on lever 572 projects into the slot or opening 548defined on bracket 530 while actuating pin 578 projects into the slot oropening 568 defined on bracket 550. As will be appreciated by thoseskilled in the art, this arrangement allows the brackets to verticallymove toward and away from each other along the rails 518 and 520 definedin the enclosure 516 of base 510 in response to manual pivotal orrocking movement of the lever 572 about the axis 575. To facilitatemovement of the lever 572, the upper end of lever 570 is provided with ahandle 580 that projects generally normal to the handle or lever 572 toreadily allow manual manipulation of the handle or lever 570.

The cover 590 for the singulator assembly 500 is schematicallyillustrated in FIGS. 43 and 44. The cover 590 preferably includes agenerally rectangular front wall 592 having a closed rim 594 extendingabout the peripheral edge thereof. Notably, the configuration of thefront wall 592 and the rim 594 closely proximates if not corresponds tothe configuration of the back wall 512 and closed rim 514 on base 510.Cover 590 furthermore includes a central throughbore or opening 596 thatis adapted to resiliently receive the free end of the mounting pin 574of lever 572. Preferably, the free end of the mounting pin 574 isconfigured to resiliently fit through the opening 596 in the front wall592 of cover 590 in a manner securing the front wall 592 of cover 590 tothe base 510 without use of further fasteners and yet allowing access tothe interior of the singulator assembly when required.

Cover 590 further defines a plurality of vertically aligned andhorizontally spaced pairs of openings 600, 602 and 604. Each verticallyaligned pair of openings 600, 602 and 604 comprises two verticallyelongated slots 606 and 608. As will be appreciated, the horizontalspacing between the pairs of openings 600, 602 and 604 is equal to thehorizontal spacings between the threaded recesses 542, 544 and 546 ofbracket 532 and the recesses 562, 564 and 566 of bracket 552. As will beappreciated, the elongated configuration of the openings 600, 602 and604 allows for vertical displacement of the brackets 530 and 550 withinthe recess 516 of the base 510.

Cover 590 furthermore defines a generally vertical upstruck and arcuatebracket 620 that is generally coplanar with the top surface 622 of thecover 590. Notably, the bracket 620 has a relatively thin constructionand thus a void or space 624 is provided on the rear side of the bracket620. It is within this space or void 624 wherein the upper end of thelever 572 moves. Moreover, the bracket 620 is configured such that thehandle 580 of lever 572 can extend thereover. Additionally, the topsurface of the bracket 620 has indicia 630 thereon for readily providinga visual indication of the position of the lever 572.

The singulator assembly 500 further comprises a series of mounting studs650 on which the singulator spools 700 are mounted. An exemplary form ofstud 650 for mounting a single singulator spool 700 to the singulatorassembly 500 is shown in FIGS. 45 and 46. As shown, each stud 650comprises an elongated member 654 having a shank portion 655 with ashouldered and externally threaded end 656 and an enlarged head portion658 at an opposite end thereof. Preferably, each stud member 654 isformed of metal. In the illustrated embodiment, each stud 650 isprovided with a series of axially extending external splines 660 axiallyextending from the head portion 658 of each stud for about one-half thelength thereof. Each stud 650 is provided with 4, 6, 8, 12 or moresplines 660 as desired. Notably, the outside diameter of the stud member654 is sized such that it is permitted to endwise pass through thevertically elongated slots 606 and 608 comprising each pair of openings600, 602 and 604 in the cover 590 of the singulator assembly 500.Moreover, the external threading at end 656 of each stud member 654corresponds to the internal threading or a metal insert (nut) within therecesses 542, 544 and 546 of bracket 530 (FIGS. 34 through 36) andwithin the recesses 562, 564 and 566 of bracket 550 (FIGS. 37 through39). Furthermore, it should be noted that the axial length of each spoolmember 702 is less than the axial distance separating the enlarged headportion 658 and the external threading 656 of each spool mounting stud650.

An exemplary form of singulator spool 700 is schematically illustratedin FIGS. 47 through 50. As shown in FIG. 47, each singulator spool 700comprises an elongated preferably metal tubular member 702 defining alongitudinal axis 704 which, when mounted to the seed meteringmechanism, extends generally normal or perpendicular to the sides of theseed disc 400. In the illustrated embodiment, and at that end 706 ofeach spool disposed closely adjacent the seed disc 400 during operationof the seed metering mechanism, each spool member 702 preferably has aseed engaging portion projecting radially outwardly from the remainderof the spool. As shown, each spool member 702 preferably has a flared orfrusto-conical seed engaging or surface configuration extending awayfrom a planar bottom surface 707 defined by the spool member 702. Asshown in FIGS. 47, 49 and 50, the flared profile at the free end 706 ofeach spool 700 increases in diameter toward end 706. Moreover, and asshown in FIGS. 47, 49 and 50, the bottom planar edge 707 of the spool700 and the flared end 706 intersect with each other to define arelative sharp edge 709 extending about the periphery of the spool 700.

As shown in FIG. 48, the peripheral edge 710 of the free end 706 ofspool member 702 has a changing or eccentric profile relative to thelongitudinal axis 704 of the spool member 702. That is, the seedengaging portion of each arcuate segment of the edge 710 of the enlargedfree end of the spool member 702 is disposed at different radialdistance from the longitudinal axis 704 of the spool member 702. Thechanging or eccentric profile allows or permits a changingcircumferential surface area of the seed deflector portion of each spool700 to be selectively positioned relative to the predetermined path oftravel of the openings thereby changing the spacing of the seeddeflector relative to the fixed path of travel of the openings 410 inthe seed disc 400 and relative to each other. In this regard, and asshown in FIG. 47, the spool member 702 has a locating mark 703 thereonfor providing a visual indication of the setting of the seed deflector706 relative to the fixed path of travel of the seeds carried by thedisc 400. In the illustrated embodiment, the locator or indicating mark703 is provided adjacent or on the seed engaging surface portion of theseed deflector. It will be appreciated, however, that the locating orindicating mark can be provided elsewhere on the spool 700 withoutdetracting or departing from the spirit and scope of the presentinvention.

As shown in FIGS. 49 and 50, each spool member 702 further defines anopening 712 extending axially through the spool member 704. As will beappreciated, rather than providing the peripheral edge 710 of the seedcontacting surface eccentric relative to the axis 704 of the spool, itis also within the spirit and scope of the present invention to providethe opening 712 in eccentric relationship relative to the spool member.

At the flared end 706, the opening 712 in each spool member 704 has anenlarged counterbore portion 714 that is sized to accommodate theenlarged head portion 658 of the mounting stud 650 (FIGS. 45 and 46).The counterbore portion 714 of opening 712 is recessed or has a depththat allows the spool to be endwise moved without exposing the headportion 658 of the spool mounting 650 therebeyond. Because the enlargedcounterbore portion 714 and the opening 712 are of different diameters,a radial wall or annular shoulder 713 is defined therebetween. Uponassembly, the enlarged head portion 658 engages with the annularshoulder 713 thereby limiting movement of the spool 700 relative to sideof the seed disc 400. As mentioned, the overall length of the spoolmember 702 is less than the length of the mounting stud 650 therebyallowing axial or endwise displacement of the spool member 702 along thelength of the stud 650. In this regard, a lengthwise portion of theopening 710 is provided with a series of internal splines 720 that areengagable with the external splines 660 on each mounting stud 650 forholding the seed engaging portion of the respective spool 700 inreleasably fixed relation relative to the axis of rotation 704.

As mentioned above, the end 706 of each spool 700 has a flared orfrusto-conical configuration. The slanted or angular configuration atthe free end 706 of the spool 700 changes as a function of the angularorientation of the slanted surface relative to the longitudinal axis 704of the spool 700. That is, the angular orientation of the flared end 706of spool 700, in the area shown by lines 49--49 in FIG. 48, is equal toabout a 45° angle relative to the planar bottom edge of the spool 700.In contrast, the angular orientation of the flared end 706 of spool 700,in the area shown by lines 50--50 in FIG. 48, may equal about 45° to 50°relative to the planar bottom edge 707 of the spool 700. As will beappreciated, the inclined surface configurations extending about theseed engaging portion of each spool defines an included angle rangingbetween about 35° and about 70° between the inclined surfaceconfiguration and the adjacent face or side of the seed disc 400.Accordingly, different effects or removal forces can be imparted to theseeds carried on the seed plate as a function of which angularorientation of the spool 700 is disposed relative to the seed pocket oropening 410 in the seed plate 400.

As will be appreciated, the changing profile of the free edge 710 allowsthe disposition of the spool 700 to be manually changed relative to thepath of movement of the openings 410 on the seed disc 400 movingtherepast. The interaction of the external spline like configurations660 on the stud 650 and the internal spline like configurations 720 onthe spool 700 prevent the spool 700 from turning or rotating relativetheir respective stud 650. Also, however, it is important to note thatthe interaction between the splines 660 and 720 allows the angularorientation of the spool 700 to be angularly adjusted as required toeffect the necessary action relative to the seeds carried by the seedplate 400 toward the discharge area of the seed metering mechanism 32 ofthe present invention. It will be readily appreciated, of course, thatthe opening 710 in the spool 700 can be eccentric relative to thelongitudinal axis 704 of the spool member 702 thereby effectingdifferent adjustments of the spool 700 relative to the circular path oftravel of the openings 410 in the seed disc 400.

Returning to FIG. 30, each spool 700 is mounted on a respective mountingstud 650 as shown. Notably, however, there is further provided acompression spring 760 or other form of resilient means for resilientlyurging the spool axially outward and away from the cover 590 toward theseed disc 400. As such, the planar bottom surface of the spool 700 isresiliently urged toward an adjacent relationship with the seed plate400 and the edge of the spool serves to engage and orient the seedstraveling toward the discharge area of the seed metering mechanism 32.The spring 760 furthermore allows the spool to be axially displacedagainst the action of the spring 760 until the cooperativeinstrumentalities, which in the illustrated embodiment includes thesplines 660 on mounting member 650 and the splines 720 of the spool 700,are released from each other thereby allowing rotation of the spool 700about the axis 714 thereby adjusting the seed engaging surface relativeto the predetermined path of the openings 410 on the seed disc 400. Asmentioned, the recessed bore 714 is sized to allow for axialdisplacement of the spool 700 relative to the mounting member 650without exposing the head portion 658 thereof. After the seed engagingportion of the spool is properly positioned relative to the path oftravel of the seed openings 410 in the disc 400, the spool 700 isautomatically returned to an operable position wherein the seed engagingportion is disposed adjacent the side of the disc 400 under theinfluence of the compression spring 760. Thereafter, the cooperatinginstrumentalities on the mounting member 650 and spool releasably holdthe seed engaging portion of the spool in fixed relation relative to theaxis 714.

With the present invention, a single singulator spool or up to sixsingulator spools can be used as part of the singulator assembly 500. Asshown in FIG. 29, in a preferred form of the invention, normally twosingulator spools 700 will be arranged to one side of the arcuate pathof travel of the openings in the seed disc 400 while at least onesingulator spool 700 will be arranged on the opposite side of thearcuate path of travel of the openings 410 in the seed disc 400. As willbe appreciated from an understanding of the present invention, thesingulator assembly 500 offers several degrees of adjustment fororientating the seeds within the pockets or openings 410 of the disc 400as well as for disengaging surplus seeds from the plate 400. First, thesingulator spool 700 may be individually adjusted by turning or rotatingthe singulator spool 700 relative to its respective mounting stud 650.Thus, different profiles on the singulator spool 700 can be properlyorientated relative to the path of travel of the openings betweenadjacent spools 700.

Alternatively, the singulator assembly 500 can be adjusted through useof the handle 570, to move the brackets 530 and 550 that carry thesingulator spools 700. As will be appreciated, movement of the brackets530 and 550 endwise within the cavity 516 defined by base 510 will movethe singulator spools 700 carried by the brackets 530 and 550 relativeto the arcuate path of travel of the openings 410 on the seed disc 400thereby further effecting adjustment of the singulator apparatus 500. Toproperly adjust the brackets 530 and 550 and the spools 700 carriedthereon relative to the fixed path of travel of the openings 410 in thedisc 400, the indicia 630 provided on the cover 590 of the singulatorapparatus 500 visually guides the operator to adjust the spools 700.

Still another salient feature of the present invention relates toimproving the release of the seeds from the seed disc 400 at thedischarge area 98 of the seed metering mechanism 32. Testing hasrevealed that imparting vibrations to the housing assembly 40 of theseed metering mechanism 32 facilitates the release of seeds from theseed plate 400 in the discharge area of the mechanism 32. In thisregard, and as shown in FIG. 11, there is preferably provided amechanism 800 for imparting vibrations to the housing assembly 40. Thevibration imparting mechanism 800 can take a myriad of shapes and sizes.Mechanism 800 can be driven in any suitable manner. Preferably, amechanism that produces vibrations in the range of about 115 hz. toabout 135 hz. appears to work well. In the illustrated form of theinvention, an electrically operated vibration type mechanism including ahousing 802 is securely fastened in and about the seed discharge area 98of the seed metering mechanism and appears to operate satisfactorily. Aswill be appreciated, the vibration mechanism 800 can be mounted insideor outside of the housing 40 without departing or detracting from thespirit and scope of the present invention. Moreover, the vibratingmechanism 800 can be secured to the cover 46 to impart vibrations to thehousing assembly 40.

From the foregoing, it will be observed that numerous modifications andvariations can be effected without departing from the true spirit andscope of the novel concept of the present invention. It will beappreciated that the present disclosure is intended as anexemplification of the invention, and is not intended to limit theinvention to the specific embodiment illustrated. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

What is claimed:
 1. A seed metering mechanism arranged in combinationwith a seed hopper capable of holding a supply quantity of seeds, saidseed metering mechanism comprising:a housing divided into a seed chamberand a vacuum chamber by a rotatable disc having a row ofcircumferentially arranged openings disposed adjacent a periphery ofsaid disc to pick up seeds under the influence of pressure differentialsacting on said disc, said housing including a seed delivery chute openat one end to said seed chamber and at an opposite end to said seedhopper to deliver seeds from said hopper to said seed chamber; and abaffle assembly operable from outside the housing to control an amountof seeds passing from said chute into said seed chamber, the baffleassembly including a baffle mounted for arcuate movement between anopened position to open the chute to the seed chamber and a closedposition to close the chute so as to prevent any seeds from passing tothe seed chamber.
 2. The seed metering mechanism according to claim 1wherein said housing comprises a stationary housing member secured tosaid seed hopper and a cover releasably joined to said housing member toallow access to an interior of said housing when the cover is removedfrom said housing member, the baffle assembly capable of closing thechute prior to removal of the cover.
 3. The seed metering mechanismaccording to claim 2 wherein said baffle is mounted to said housingmember.
 4. The seed mechanism according to claim 1 wherein said baffleis arranged in an interior of said housing, and further wherein alinkage assembly is arranged exteriorly of said housing and operablycoupled to said baffle for manual adjustment of the position of saidbaffle between the opened position and the closed position to therebycontrol the flow of seeds from said hopper into said seed chamber.
 5. Aseed metering mechanism arranged in combination with a seed hopperadapted to carry a supply quantity of seed, said seed metering mechanismcomprising:a housing having a generally disc shaped back wall with anadjoining circumferentially disposed side wall extending therefrom toform a generally cylindrical configuration, the housing furtherincluding a central hub axially extending from an interior surface ofsaid back wall toward a front wall of said housing, and wherein saidback wall has an opening therethrough with a seed chute communicatingwith said opening and extending along an exterior surface of said backwall to said hopper to direct seeds from the hopper to said housing; adisc mounted for rotation about a fixed axis to divide said housing intoa vacuum chamber and a seed chamber, said seed chamber receiving seedsthrough said opening in the back wall of said housing; and a baffleassembly operable from outside the housing to control an amount of seedspassing from said chute into said seed chamber, the baffle assemblyincluding a baffle mounted for arcuate movement between an openedposition to open the chute to the seed chamber and a closed position toclose the chute so as to prevent any seeds from passing to the seedchamber.
 6. The seed metering mechanism according to claim 5 whereinsaid housing includes a stationary housing member and a cover releasablysecured to said housing member to permit access to an interior of saidhousing.
 7. The seed metering mechanism according to claim 6 whereinsaid cover is releasably removable from said housing to permit access tothe interior of said housing, the baffle assembly capable of closing thechute prior to removal of the cover.
 8. The seed metering mechanismaccording to claim 6 wherein said cover defines a vacuum port to which avacuum source is connected to cause reduced pressure to be created insaid vacuum chamber.
 9. The seed metering mechanism according to claim 5wherein said seed chute is formed integrally with the back wall of saidhousing.
 10. The seed metering mechanism according to claim 5 whereinsaid baffle includes a planar member mounted for arcuate movement aboutsaid hub and configured to extend across the entirety of said opening inthe back wall of said housing when in the closed position to preventseeds from passing into said seed chamber.
 11. The seed meteringmechanism according to claim 5 wherein said baffle includes a firstportion radially disposed to one side of said hub and configured toextend across the entirety of the opening in the back wall of saidhousing when in the closed position to prevent seeds from passing intothe seed chamber, and a second portion radially disposed to an oppositeside of said hub and capable of being exteriorly adjusting to controlarcuate movement of the baffle.
 12. The seed metering mechanismaccording to claim 5 wherein said baffle is arranged in generally flushrelation relative to the interior surface of the back wall of saidhousing and configured to extend across the entirety of the opening inthe back wall when in the closed position thereby preventing seeds frompassing from said chute into the seed chamber, the baffle assemblyfurther including a linkage assembly arranged on the exterior surface ofthe back wall of said housing and in communication with the baffle tothe permit position of the baffle to be adjusted from outside thehousing.
 13. The seed metering mechanism according to claim 12 whereinthe baffle includes a first portion radially disposed to one side of thehub and configured to extend across the entirety of the opening when inthe closed position and a second portion radially disposed to anopposite side of the hub, said linkage assembly is operably connected tothe second portion of said baffle.
 14. The seed metering mechanismaccording to claim 12 wherein said linkage assembly has a plurality ofset positions relative to said housing, and wherein the set positions ofsaid linkage assembly correspond to different set positions for saidbaffle relative to said opening in the back wall of said housing andthereby different seed flow rates between the seed hopper and the seedchamber of said housing.
 15. The seed metering mechanism according toclaim 12 wherein said linkage assembly is releasably securable to saidhousing in several predetermined positions, with each position of saidlinkage position relative to said housing corresponding to a differentposition for said baffle relative to said opening in the back wall ofsaid housing and thereby providing a different seed flow rate betweenthe seed hopper and the seed chamber of said housing.
 16. A vacuum seedmetering mechanism arranged in combination with a seed hopper adapted tocarry a supply quantity of seed, said seed metering mechanismcomprising:a two-piece housing assembly having a generally disc shapedback wall with an adjoining circumferentially disposed side wallextending therefrom to form a generally cylindrical configuration, acentral hub axially extending from an interior generally planar surfaceof said back wall toward a cover forming part of said housing assembly,and wherein said back wall has an opening formed therethrough with aseed chute formed on said back wall and communicating with said openingto direct a gravitational flow of seeds from the hopper to said housingassembly; a disc mounted for rotation about a fixed axis to divide saidhousing into a vacuum chamber and a seed chamber, said seed chamberreceiving seeds through said opening in the back wall of said housingassembly, and wherein said disc moves said seeds from said seed chambertoward a discharge area under the influence of pressure differentialsacting on said seeds; and a baffle assembly operable from outside thehousing assembly to control a quantity of seeds gravitationally passingfrom said chute into said seed chamber while maintaining said cover inassembled relation relative to said housing assembly, the baffleassembly including a baffle mounted for arcuate movement between anopened position to open the chute to the seed chamber and a closedposition to close the chute so as to prevent any seeds from passing tothe seed chamber.
 17. The seed metering mechanism according to claim 16wherein said baffle includes a planar member arranged in abuttingrelation relative to the planar interior surface of the back wall ofsaid housing assembly for arcuate movement about said hub and configuredto extend across the entirety of said opening in the back wall of saidhousing assembly to prevent seeds from gravitationally passing into saidseed chamber when in the closed position.
 18. The seed meteringmechanism according to claim 16 wherein said baffle includes a firstportion radially disposed to one side of said hub and configured toextend across the entirety of the opening in the back wall of saidhousing assembly when in the closed position to prevent seeds fromgravitationally passing into the seed chamber, and a second portionradially disposed to an opposite side of said hub and capable of beingexteriorly adjusted to control arcuate movement of the baffle.
 19. Theseed metering mechanism according to claim 18 wherein said bafflefurther includes a linkage assembly arranged on the exterior surface ofthe back wall of said housing assembly and operably connected to thesecond portion of said baffle to permit the baffle to be exteriorlyadjusted while maintaining said housing assembly in assembled relation.20. The seed metering mechanism according to claim 19 wherein saidlinkage assembly has a plurality of set positions relative to saidhousing assembly, and wherein the set positions of said linkage assemblycorrespond to different set positions for said baffle relative to saidopening in the back wall of said housing assembly and thereby differentseed flow rates between the seed hopper and the seed chamber of saidhousing assembly.
 21. The seed metering mechanism according to claim 20wherein a flange extends from the exterior surface of the housingassembly, wherein said flange is provided with a series of spaceddetents for releasably accommodating a portion of said linkage assemblytherein and in predetermined positions, with each detent correspondingto a different setting for said baffle relative to said opening in theback wall of said housing assembly and thereby establishing a differentseed flow rate between the seed hopper and the seed chamber of saidhousing assembly.